Prevention of Unintentional Islands in Power Systems with Distributed Resources

The webinar, Prevention of Unintentional Islands in Power Systems with Distributed Resources, was given to the New York State Interconnection Technical Working Group in August 2016.

Technical Report

Prevention of Unintentional Islands in Power Systems with Distributed Resources (Ben Kroposki 2016) 
This webinar presented on August 24, 2016, featured a presentation by NREL's Power Systems Engineering Center Director Ben Kroposki.

Topics Covered

  • History and evolution of unintentional requirements
  • Types of islands in power systems with distributed resources
  • Issues with unintentional islands
  • Methods of protecting against unintentional islands
  • Standard testing for unintentional islanding
  • Advanced testing of inverters for anti-islanding functionality
  • Probability of unintentional islanding
  • The future of anti-islanding protection

Key Takeaways

There are many methods of preventing unintentional islanding, including certain types of relays, passive and active anti-islanding capabilities built into the inverter, and external, communication-based anti-islanding methods. New methods such as based on phasor measurements are in development.

Testing methods are detailed in IEEE Std 1547.1. Power hardware-in-the-loop can be used to simulate conditions difficult to achieve with components alone. Results from testing of scenarios with multiple inverters have been published, however additional research is needed for more types of configurations and equipment designs.

Suggested guidelines for assessment of unintentional islanding risk have been published by Sandia. As the power system evolves, new types of anti-islanding are likely to emerge.

Watch